External storage upload causes app to hang

[allaway]

Describe the bug
When annotating a dataset on external S3 storage, often we will be annotatting data where Synapse only has READ access to the bucket. The app/schematic will try to write the synapse_metadata_manifest file to the bucket, but it just sits there forever because we do not have bucket write access. The files are still successfully annotated, so this is a minor problem for us, since we rely on that as our ground truth.

To Reproduce
Steps to reproduce the behavior:

1. Go an external bucket dataset with READ only access.
2. Annotate
3. App will hang (see log file below)

Expected behavior
Check for write access, or alternatively, write synapse_metadata_manifest to local synapse storage, not external bucket.

Priority (select one)

• Minor ⬇️
• Major 📢
• Critical 🆘

Additional context

2022-05-23T22:41:30.365822+00:00 shinyapps[5711947]: ##################################################
2022-05-23T22:41:30.365896+00:00 shinyapps[5711947]:  Uploading file to your external S3 storage 
2022-05-23T22:41:30.365970+00:00 shinyapps[5711947]: ##################################################
2022-05-23T22:41:30.366033+00:00 shinyapps[5711947]: 
2022-05-23T22:41:30.366106+00:00 shinyapps[5711947]: /srv/connect/apps/NF_data_curator-staging/.venv/lib/python3.8/site-packages/synapseclient/table.py:1968: DtypeWarning: Columns (56) have mixed types.Specify dtype option on import or set low_memory=False.
2022-05-23T22:41:30.366183+00:00 shinyapps[5711947]:   return _csv_to_pandas_df(self.filepath,
2022-05-23T22:41:30.366247+00:00 shinyapps[5711947]: INFO: [2022-05-23 22:41:29] synapseclient_default - 
2022-05-23T22:41:30.366304+00:00 shinyapps[5711947]: ##################################################
2022-05-23T22:41:30.366488+00:00 shinyapps[5711947]: 
2022-05-23T22:41:30.366370+00:00 shinyapps[5711947]:  Uploading file to your external S3 storage 
2022-05-23T22:41:30.366427+00:00 shinyapps[5711947]: ##################################################